Small alternator?

[TrackTV6]

Got any ideas on what is a good small sized alternator?

 

[benT]

Got any ideas on what is a good small sized alternator?

Both Dad and I are running the small chrome 50a denso type alternators. Got mine off ebay from this vendor: dbelectrical

 

[Rogers23T]

Nice alt, however did you ask your self how much power are you gonna need before buying one. If you have an aftermarket ignition set up like MSD you may need more than 50-60 amps.

 

[benT]

50a is plenty for what we are running. Neither of our cars runs radios,msd's or anything like that. I figure I could get by with as little as a 35-40 amps. Anyway, both our cars have thousands of miles with those Alts with no issues.

 

[Hotrod46]

Nice alt, however did you ask your self how much power are you gonna need before buying one. If you have an aftermarket ignition set up like MSD you may need more than 50-60 amps.

I am running a small Denso alternator from a Geo Metro (55 amps) and a MSD6 AL 2 ignition. No problems in 10000 miles.

I also have a Carter electric fuel pump ,air suspension compressor for the rear that runs intermittently, halogen headlights and four taillights with 1157 bulbs. Voltmeter stays on 14.2 during the day and drops to 14 with all lights on. Might be a problem if I ran an electric fan, though.

Mike

 

[Rogers23T]

Good post guys... The reason I made my statement is because I will be running ; halogen headlights, rear led lights, holley ele fuel pump, ele fan, msd 6al box with blaster 2 coil, and a few gauges with lights. I figured I'll need at least 65 amps

 

[TrackTV6]

Went to our local Pull-n-Save parts store and removed one from a 1991 Geo Prizm. I'll post some pictures soon

 

[Wild Mango]

Good post guys... The reason I made my statement is because I will be running ; halogen headlights, rear led lights, holley ele fuel pump, ele fan, msd 6al box with blaster 2 coil, and a few gauges with lights. I figured I'll need at least 65 amps

Whew, thats around 780 watts load you allowed for. Allowing 25W for the instrument lites, 80W for the fan, 100W for the ignition, 140W for the headlites, 20W for the LED tails, 100W for the pump, and 120W for battery charging gets us say 585W or 49A give or take. With a proper 17 plate battery (not one of those tiny pantywaist "green" things) to supply peaking power when you need it a 50A alternator will serve you well, IMHO. The fuel pump and the fan won't run all the time as well.

 

[Rogers23T]

Lets just say for the sake of arguement, I have a draw of.. 10 amps for ign sys, 20 amps for ele fan, 5amps for fuel pump (yes holley's run all the time), 15 amps for the 2 halogen headlights, 5 amps for the gauges... Already at 55 amps!, that without the small draw of LED back lights. So I believe that a 65 amp is gonna be needed just to have some charging even with a draw of approx 55 amps. Mind you this is all saying everything is maxed out, my old saying better safe than sorry. I just don't wanna come to a stop at a light and see the headlight dim due to not enought rpm or/ie power to run the draw aginist the system.

 

[Wild Mango]

Lets just say for the sake of arguement, I have a draw of.. 10 amps for ign sys, 20 amps for ele fan, 5amps for fuel pump (yes holley's run all the time), 15 amps for the 2 halogen headlights, 5 amps for the gauges... Already at 55 amps!, that without the small draw of LED back lights. So I believe that a 65 amp is gonna be needed just to have some charging even with a draw of approx 55 amps. Mind you this is all saying everything is maxed out, my old saying better safe than sorry. I just don't wanna come to a stop at a light and see the headlight dim due to not enought rpm or/ie power to run the draw aginist the system.

Yes, good points. Stand corrected on the fuel pump. I usually calculate loads in watts (amps X volts), sum them up and divide by 12 to get a nominal current, because with the alternator on line the voltage is going to be more like 13 - 14V provided it's running within capacity. Electrical machines like alternators are at their most efficient running at rated capacity, and RPM. The RPM is important for cooling air as well as output. As you rightly say, irrespective of rating, rated output isn't at idle, and Mr Battery makes up the shortfall when your'e sitting at the lights. So if you got the dreaded yellow headlights at idle, Mr Battery or his wiring is due for some attention. Yep, better bigger than regretful, and when you move off the lights and come up to cruise there is going to be a need for extra capacity in the charging system to pay the battery back for it's idle contribution.

 

[TrackTV6]

I built some brackets for the small Denso alternator today. Also did a little research and found that in the early 90's Toyota used this same alternator on some Camrys and it has a 70 amp output. So if this one doesn't meet my needs, I can switch without building new brackets.